A GNSS receiver can be used on any type of vehicle to determine information about its position, its speed and generally to provide an aid to movement or to navigation.
In particular, such a receiver can be used on a space launcher. The use of a mono-antenna receiver in such a case of application poses a problem since the vertical position of the fuselage of the craft gives rise to a masking of a part of the satellites in view by the body of the launcher for the antennas. The signals transmitted by these satellites will then not be received or be received with a strong attenuation by the receiver. In a more general manner, the positioning of an antenna on the body of a carrier of large wingspan poses the problem of the masking of all or part of the radio-navigation signals emitted by the satellites in view of the carrier by the carrier itself.
A solution making it possible to solve the problem of signals masking consists in using an annular antenna disposed around the circumference of the fuselage of the carrier. In this manner, the signal emitted by a satellite is permanently received by at least one part of the antenna. However, this type of antenna does not make it possible to achieve satisfactory performance since it produces a single signal output which is constructed in a non-optimal manner and which gives rise to significant losses in signal-to-noise ratio.
The invention makes it possible to solve the aforementioned problem by proposing a solution which improves performance with respect to the known receivers. The invention consists in using a plurality of antennas disposed around the circumference of the fuselage of the craft and in demodulating the signals received by each antenna separately. The diversity of the demodulation chains is utilized to compensate the signal loss on one of the chains when the corresponding antenna experiences a signal loss due to the masking of the satellite by the carrier.